Gravel between floors

[Ken Knowles]

I live in a house built in late 30s and while installing some network cabling between the ground and first floor I drilled through the ceiling to be showered in black gravel. No harm done but I jst wondered if anyone had any idea what it was and why it would be located between the ground floor ceiling and first floor boards?

 

[RandomGrinch]

Some of it may look a bit like clinker from an open fire, but I'm not convinced.
Do you by any chance live in Scotland?
An odd question, but I have anecdotally heard of all sorts being chucked into the floor voids of tenaments to add sound insulation.
How this would translate to your house, I have no idea!

 

[Ken Knowles]

Thanks for the reply. I do live in Scotland (semi detached, not a tenement), so maybe some sort of sound insulation. There was a chimney but on the opposite side of the room so I would assume any open fire would be on the opposite side of where I was drilling. The material is carbon black when crushed so seemed like maybe some sort of fire detritus. Very strange!

 

[RandomGrinch]

Sometimes traditional building practice may be carried over, even when it's not required!
Whether it extends over the whole floor area would be interesting to know.
Hope you were ok when that lot came down on you!

 

[Ken Knowles]

Yeah just an unexpected surprise to have to clean up - fortunately i was only drilling a small hold for a cat6 cable!

 

[JohnD]

it used to be called pugging.

 

[KenGMac]

Ken Knowles, good evening.

Up here old ash deafening is extremely common, there must be several hundred thousand properties with Ash between floors, and it is actually quite effective at noise reduction.

Ash was [back in the day] cheap and plentiful the Old Builders found that if placed between the joists it worked well, it was installed by fixing two length ways straps of [any] timber to the sides of the joists, then any scrap timber was fitted, resting on these two straps and the ash was filled on to the platform.

What you appear to have been cascades with is a modern alternative??? called "Quietex" this material "Quietex" is still used, my son lives in an Ex Housing Association adapted Glasgow tenement flat, the H/Ass did a make over a long time back and removed the Ash but replaced it with "Quietex"

One serious drawback is that if the old flat is seriously flooded the Ash has to be removed and replaced with a modern equivalent, the "removal" is a really filthy job.

Ken.

 

[Ken Knowles]

Well that answers the question, thanks. Maybe it also explains why my wifi signal is so badly attenuated between floors, which was the reason for having to drill the hole in the first place!